And they did just that. Again. A 90-yard touchdown drive fittingly capped off by rookie quarterback Russell Wilson’s 1-yard scramble was the difference in Seattle’s 20-13 victory Sunday over St. Louis at CenturyLink Field.

A regular season that started with Seattle coming up 4 yards short on the road in Arizona ended with Seattle driving the length of the field to finish undefeated at home for the third time in franchise history.

With San Francisco beating Arizona to clinch the NFC West title, Seattle’s victory had absolutely no impact on the Seahawks’ playoff positioning that sends them to Washington next Sunday at 1:30 p.m., and everything to do with their readiness for the postseason. And after three weeks of historically lopsided blowouts, the nail-biting Sunday was perfect preparation for what lies ahead.

“It definitely gave us an example of what to expect in the playoffs,” defensive end Red Bryant said.

The game went right down to the final minute, cornerback Richard Sherman intercepting St. Louis’ Sam Bradford in the Seattle end zone to seal the victory.

The Seahawks came into the game having scored more points the previous three weeks than any NFL team in 62 years, but managed only a field goal in the first half. That three-point halftime total stood out after the past three games in which Seattle scored at least seven points in all but one quarter.

Seattle had a 28-yard touchdown catch by Zach Miller negated by a penalty in the first half, and a defensive score overturned on replay review in the second half.

The Seahawks trailed for the first time in three weeks, and allowed more sacks to the Rams in the first half than they had given up in any game this season.

Seattle had the ball inside the Rams’ 20-yard line once in the first half only to have tackle Breno Giacomini penalized for a false start, stalling a drive in which Seattle ultimately settled for a field goal.

It was a flashback to the first month of the season, the Seahawks scrounging for points while its defense played admirably.

Then in the second half, Seattle showed how much it has changed since September. At least Wilson showed that.

His 10-yard touchdown pass to fullback Michael Robinson in the third quarter gave Seattle a 13-10 lead and tied the NFL’s rookie record for touchdown passes in a season at 26.

It was after the Rams tied the game at 13-13 that Wilson led the Seahawks on a drive that demonstrated why Seattle is entering the playoffs with the second-longest winning streak in the NFC.

“In a quarterback-driven league, we go as our quarterback goes,” Robinson said. “When he’s on, man, there’s not many people better than him.”

That 90-yard drive embodied Robinson’s point perfectly. With Seattle facing third-and-five from its 27-yard-line, the Rams brought pressure up the middle only to have Wilson duck in the pocket, roll out to his right and loft a perfectly placed pass to Golden Tate for a 44-yard gain.

Three plays later, Wilson kept the ball on an option play, running to his left for 15 yards, injuring cornerback Janoris Jenkins during the tackle and giving Seattle first-and-goal at the St. Louis 4.

Marshawn Lynch appeared to score on the next play only to have his touchdown overruled by replay review.

Wilson’s 1-yard touchdown scramble on the next play was a fitting conclusion, the rookie dropping back to pass only to see everyone covered and finding his way into the end zone.

“I’m really proud of the way these guys finished,” coach Pete Carroll said.